I've used Onkyo, HK, and Pioneer receivers and the best one for me has been my Pioneer Elite 92. I had it running all of my speakers and it sounded wonderful, but I'm a believer in outboard amps to run the front end, so now I've some inexpensive (nad2100, two nad2155) amps to run the front end and it's quite amazing!
I'm sure the denon and yamaha receivers are just as robust and full featured as the Pioneers, but I really do think that the Pioneer AVRs are much 'sexier'.
Goodluck with your purchase!